From d0dda804153175636ebe0f2850263c8825b6d791 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Wed, 13 Sep 2017 15:07:44 +0100 Subject: [PATCH] PR libstdc++/81468 constrain std::chrono::time_point constructor PR libstdc++/81468 * include/std/chrono (__enable_if_is_duration) (__disable_if_is_duration): New alias templates to simplify SFINAE. (duration_cast, floor, ceil): Use __enable_if_is_duration. (duration::__is_float, duration::__is_harmonic): New alias templates to simplify SFINAE. (duration::duration(const _Rep2&)): Use _Require, __is_float and __is_harmonic. (duration::duration(const duration<_Rep2, _Period2>&)): Likewise. (__common_rep_type): Remove, replace with ... (__common_rep_t): New alias template. (operator*, operator/, operator%): Use __common_rep_t and __disable_if_is_duration. (time_point::time_point(const time_point&)): Add missing constraint from LWG DR 1177. * testsuite/20_util/duration/cons/dr1177.cc: New. * testsuite/20_util/duration/literals/range.cc: Update dg-error line. * testsuite/20_util/duration/requirements/typedefs_neg1.cc: Likewise. * testsuite/20_util/duration/requirements/typedefs_neg2.cc: Likewise. * testsuite/20_util/duration/requirements/typedefs_neg3.cc: Likewise. * testsuite/20_util/time_point/cons/81468.cc: New. From-SVN: r252085 --- libstdc++-v3/ChangeLog | 22 ++++++ libstdc++-v3/include/std/chrono | 75 +++++++++++-------- .../testsuite/20_util/duration/cons/dr1177.cc | 41 ++++++++++ .../20_util/duration/literals/range.cc | 2 +- .../duration/requirements/typedefs_neg1.cc | 2 +- .../duration/requirements/typedefs_neg2.cc | 2 +- .../duration/requirements/typedefs_neg3.cc | 2 +- .../20_util/time_point/cons/81468.cc | 34 +++++++++ 8 files changed, 144 insertions(+), 36 deletions(-) create mode 100644 libstdc++-v3/testsuite/20_util/duration/cons/dr1177.cc create mode 100644 libstdc++-v3/testsuite/20_util/time_point/cons/81468.cc diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 0c3ee2a42c8..36a9744fb4a 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,27 @@ 2017-09-13 Jonathan Wakely + PR libstdc++/81468 + * include/std/chrono (__enable_if_is_duration) + (__disable_if_is_duration): New alias templates to simplify SFINAE. + (duration_cast, floor, ceil): Use __enable_if_is_duration. + (duration::__is_float, duration::__is_harmonic): New alias templates + to simplify SFINAE. + (duration::duration(const _Rep2&)): Use _Require, __is_float and + __is_harmonic. + (duration::duration(const duration<_Rep2, _Period2>&)): Likewise. + (__common_rep_type): Remove, replace with ... + (__common_rep_t): New alias template. + (operator*, operator/, operator%): Use __common_rep_t and + __disable_if_is_duration. + (time_point::time_point(const time_point&)): Add missing + constraint from LWG DR 1177. + * testsuite/20_util/duration/cons/dr1177.cc: New. + * testsuite/20_util/duration/literals/range.cc: Update dg-error line. + * testsuite/20_util/duration/requirements/typedefs_neg1.cc: Likewise. + * testsuite/20_util/duration/requirements/typedefs_neg2.cc: Likewise. + * testsuite/20_util/duration/requirements/typedefs_neg3.cc: Likewise. + * testsuite/20_util/time_point/cons/81468.cc: New. + * doc/doxygen/mainpage.html: Fix broken URLs. PR libstdc++/81835 diff --git a/libstdc++-v3/include/std/chrono b/libstdc++-v3/include/std/chrono index 1bcbf524a7b..fc058fcd8d8 100644 --- a/libstdc++-v3/include/std/chrono +++ b/libstdc++-v3/include/std/chrono @@ -179,10 +179,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION : std::true_type { }; + template + using __enable_if_is_duration + = typename enable_if<__is_duration<_Tp>::value, _Tp>::type; + + template + using __disable_if_is_duration + = typename enable_if::value, _Tp>::type; + /// duration_cast template - constexpr typename enable_if<__is_duration<_ToDur>::value, - _ToDur>::type + constexpr __enable_if_is_duration<_ToDur> duration_cast(const duration<_Rep, _Period>& __d) { typedef typename _ToDur::period __to_period; @@ -211,7 +218,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION # define __cpp_lib_chrono 201510 template - constexpr enable_if_t<__is_duration<_ToDur>::value, _ToDur> + constexpr __enable_if_is_duration<_ToDur> floor(const duration<_Rep, _Period>& __d) { auto __to = chrono::duration_cast<_ToDur>(__d); @@ -221,7 +228,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } template - constexpr enable_if_t<__is_duration<_ToDur>::value, _ToDur> + constexpr __enable_if_is_duration<_ToDur> ceil(const duration<_Rep, _Period>& __d) { auto __to = chrono::duration_cast<_ToDur>(__d); @@ -294,6 +301,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template struct duration { + private: + template + using __is_float = treat_as_floating_point<_Rep2>; + + // _Period2 is an exact multiple of _Period + template + using __is_harmonic + = __bool_constant::den == 1>; + + public: + typedef _Rep rep; typedef _Period period; @@ -305,22 +323,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // 20.11.5.1 construction / copy / destroy constexpr duration() = default; - // NB: Make constexpr implicit. This cannot be explicitly - // constexpr, as any UDT that is not a literal type with a - // constexpr copy constructor will be ill-formed. duration(const duration&) = default; - template::value - && (treat_as_floating_point::value - || !treat_as_floating_point<_Rep2>::value)>::type> + template, + __or_<__is_float, __not_<__is_float<_Rep2>>>>> constexpr explicit duration(const _Rep2& __rep) : __r(static_cast(__rep)) { } - template::value - || (ratio_divide<_Period2, period>::den == 1 - && !treat_as_floating_point<_Rep2>::value)>::type> + template, + __and_<__is_harmonic<_Period2>, + __not_<__is_float<_Rep2>>>>>> constexpr duration(const duration<_Rep2, _Period2>& __d) : __r(duration_cast(__d).count()) { } @@ -455,18 +469,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return __cd(__cd(__lhs).count() - __cd(__rhs).count()); } - template::type>::value> - struct __common_rep_type { }; - - template - struct __common_rep_type<_Rep1, _Rep2, true> - { typedef typename common_type<_Rep1, _Rep2>::type type; }; + // SFINAE helper to obtain common_type<_Rep1, _Rep2> only if _Rep2 + // is implicitly convertible to it. + template::type> + using __common_rep_t + = typename enable_if::value, _CRep>::type; template - constexpr - duration::type, _Period> + constexpr duration<__common_rep_t<_Rep1, _Rep2>, _Period> operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s) { typedef duration::type, _Period> @@ -475,14 +486,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } template - constexpr - duration::type, _Period> + constexpr duration<__common_rep_t<_Rep2, _Rep1>, _Period> operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d) { return __d * __s; } template - constexpr duration::value, _Rep2>::type>::type, _Period> + constexpr + duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period> operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s) { typedef duration::type, _Period> @@ -504,8 +514,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // DR 934. template - constexpr duration::value, _Rep2>::type>::type, _Period> + constexpr + duration<__common_rep_t<_Rep1, __disable_if_is_duration<_Rep2>>, _Period> operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s) { typedef duration::type, _Period> @@ -614,7 +624,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { } // conversions - template + template>> constexpr time_point(const time_point& __t) : __d(__t.time_since_epoch()) { } diff --git a/libstdc++-v3/testsuite/20_util/duration/cons/dr1177.cc b/libstdc++-v3/testsuite/20_util/duration/cons/dr1177.cc new file mode 100644 index 00000000000..28c881ccc79 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/duration/cons/dr1177.cc @@ -0,0 +1,41 @@ +// Copyright (C) 2017 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do compile { target c++11 } } + +#include +#include + +using namespace std; +using namespace std::chrono; + +// DR 1177 +static_assert(is_constructible, duration>{}, + "can convert duration with one floating point rep to another"); +static_assert(is_constructible, duration>{}, + "can convert duration with integral rep to one with floating point rep"); +static_assert(!is_constructible, duration>{}, + "cannot convert duration with floating point rep to one with integral rep"); +static_assert(is_constructible, duration>{}, + "can convert duration with one integral rep to another"); + +static_assert(!is_constructible, duration>>{}, + "cannot convert duration to one with different period"); +static_assert(is_constructible, duration>>{}, + "unless it has a floating-point representation"); +static_assert(is_constructible, duration>>{}, + "or a period that is an integral multiple of the original"); diff --git a/libstdc++-v3/testsuite/20_util/duration/literals/range.cc b/libstdc++-v3/testsuite/20_util/duration/literals/range.cc index b5105dff38b..36e71eea72b 100644 --- a/libstdc++-v3/testsuite/20_util/duration/literals/range.cc +++ b/libstdc++-v3/testsuite/20_util/duration/literals/range.cc @@ -26,6 +26,6 @@ test01() // std::numeric_limits::max() == 9223372036854775807; auto h = 9223372036854775808h; - // { dg-error "cannot be represented" "" { target *-*-* } 880 } + // { dg-error "cannot be represented" "" { target *-*-* } 891 } } // { dg-prune-output "in constexpr expansion" } // needed for -O0 diff --git a/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg1.cc b/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg1.cc index 17f74187098..d57f6dedd66 100644 --- a/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg1.cc +++ b/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg1.cc @@ -30,4 +30,4 @@ void test01() test_type d; // { dg-error "required from here" } } -// { dg-error "rep cannot be a duration" "" { target *-*-* } 300 } +// { dg-error "rep cannot be a duration" "" { target *-*-* } 318 } diff --git a/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg2.cc b/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg2.cc index 282a9dbdc85..39283b2cb74 100644 --- a/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg2.cc +++ b/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg2.cc @@ -31,5 +31,5 @@ void test01() test_type d; // { dg-error "required from here" } } -// { dg-error "must be a specialization of ratio" "" { target *-*-* } 301 } +// { dg-error "must be a specialization of ratio" "" { target *-*-* } 319 } // { dg-prune-output "not a member" } diff --git a/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg3.cc b/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg3.cc index c57f9d947a5..9beaa83fbfa 100644 --- a/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg3.cc +++ b/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg3.cc @@ -32,4 +32,4 @@ void test01() test_type d; // { dg-error "required from here" } } -// { dg-error "period must be positive" "" { target *-*-* } 303 } +// { dg-error "period must be positive" "" { target *-*-* } 321 } diff --git a/libstdc++-v3/testsuite/20_util/time_point/cons/81468.cc b/libstdc++-v3/testsuite/20_util/time_point/cons/81468.cc new file mode 100644 index 00000000000..30d1c4a5ac7 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/time_point/cons/81468.cc @@ -0,0 +1,34 @@ +// Copyright (C) 2017 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do compile { target c++11 } } + +#include +#include + +using namespace std; +using namespace std::chrono; + +template + using sys_time = time_point; + +static_assert(is_constructible, sys_time>{}, + "Can construct time_point from one with lower precision duration"); + +// PR libstdc++/81468 - DR 1177 +static_assert(!is_constructible, sys_time>{}, + "Cannot construct time_point from one with higher precision duration"); -- 2.30.2